The pilot was making a landing approach at the conclusion of a scenic flight. There were horses on the strip and the pilot elected to land long. The aircraft bounced on touchdown and recovery action was not effective before further bounces occurred. The pilot in the right hand seat took control and applied full power, however the aircraft settled into trees adjacent to the strip, and overturned. The strip surface was undulating and the landing was attempted in gusting crosswind conditions. The pilot occupying the right front seat had boarded the aircraft as a passenger. He had taken control of the aircraft because the actions of the pilot in command, following the bounced landing, were ineffective and the aircraft was heading for a building beside the strip. He had no instructional experience.

On the day preceding the accident the station manager was informed that the pilot hired to carry out the muster would be late in arriving. He asked a stockman, who was a station employee, if he would carry out spotting duties until the other pilot arrived. About 20 minutes after the operation had commenced, the ground party heard the sounds of an aircraft impact. The pilot stated that he had been flying at between 400 and 500 feet above the ground when he lost control of the aircraft in a turn. The aircraft was discovered to have struck the ground while in a nose-low, stalled condition. The engine was not developing power at the time of impact, however no defect was subsequently found with the engine or systems of the aircraft. The pilot did not hold a mustering endorsement and had apparently not received formal training in low level operations.

Following a period of circuit practice, the instructor was demonstrating some enroute emergency procedures. An autorotation was entered from 2000 feet, with the pilot aiming for a paddock on the side of a river. He advised that descent was continued to about 250 feet above the ground. Shortly after power was re-applied the helicopter collided with a set of power lines and dived to the ground. The pilot had noted two other sets of wires in the area, but had not sighted a set of three cables between the others until immediately before the collision. The helicopter was being operated outside the designated training area. The grey oxidised powerlines, which were estimated to be between 80 and 100 feet above ground level, were very difficult to see against the overcast sky conditions. The span between supporting poles was greater than those between the other sets of cables.

The pilot was conducting the second leg of his first solo cross-country exercise. He subsequently reported that during the takeoff the aircraft failed to become airborne when expected. Power was reduced in order to abandon the attempt, but the aircraft then momentarily became airborne. The pilot applied forward pressure to the control column to place the aircraft back onto the ground, but a heavy touchdown occurred. The nosegear collapsed and the aircraft slid for 183 metres before coming to a stop. After vacating the aircraft, the pilot realised that he had attempted to takeoff with a downwind component of about 10 to 15 knots. The pilot stated that he had not considered the wind direction prior to the takeoff attempt due to his feeling of elation after successfully completing the first leg of his first solo navex. The runway assumes a downslope past the intersection and the pilot misidentified the gable markers near the runway intersection as delineating the end of the strip. From the position at which the aircraft came to rest there were 917 metres remaining of the 1900 metre strip.

Prior to touchdown the gear position indicator indicated that the gear was down. During the landing roll the right main gear collapsed and the right wing, engine, propeller and flap struck the ground. Collapse of the right maingear resulted from excessive wear of the right overcentre lock bush bearing. The reason for the excessive rate of wear of the bush could not be determined. Thirty six landings had been recorded since the last scheduled maintenance inspection of the gear and it is considered that some evidence of the excessive wear should have been present at that inspection.

Three helicopters were engaged in the mustering of cattle on the property. One became unserviceable during the afternoon but returned to the muster after rectification. By 1830 hours the herd of 4000 cattle were near the homestead and one of the pilots was instructed to return to the homestead and land. The other two helicopters continued the muster using the landing lights of the aircraft for lighting. Last light in the area was 1842 hours. At about 1910 hours the muster was nearing completion and the pilot of VH-HMX was instructed by the property overseer to move his aircraft away from the herd. Shortly afterwards the pilot of the other aircraft observed a fire, and upon investigation found the wreckage of VH-HMX. The aircraft had struck the ground in a steep nose down attitude while banked at about 90 degrees to the left. The pilot was neither approved nor qualified to conduct night mustering operations. An inspection of the wreckage found that the landing light had failed prior to impact, however, due to the damage to the helicopter no reason for the failure could be established. It is considered likely that while the helicopter was being turned away from the cattle, the landing light failed and with the the resulting loss of visual cues the pilot became disoriented and lost control of the aircraft.

The aircraft had not flown since December 1985 and had been parked in the open. The Maintenance Release had expired, and a Permit to Fly was obtained to allow the aircraft to be ferried to Parafield for maintenance. When the gear was lowered for landing, only the nosegear indicated that it was down and locked. Recycling the system did not result in locked indications being obtained for the maingear, although to persons on the ground it appeared to be down. During the subsequent landing roll the right gear collapsed. The aircraft had been inspected prior to the flight and the engineers had noted that the gear bearings were dry and slightly corroded. They did not bring this to the attention of the pilot and he did not detect the condition during the preflight inspection. When the gear failed to fully extend prior to landing, because of lack of lubrication and corrosion, the pilot discussed the situation with an engineer on the aircraft and they decided that the fault was probably in the gear position indication system. As a result no attempt was made to lower the gear using the emergency system.

Following the first 50 hour oil change after a recent overhaul, the engineer who completed the overhaul and service, arranged for he and his wife to accompany the pilot on a scenic flight of the local area. The flight was conducted at an altitude of about 400 feet above ground level and proceeded normally for about 15 minutes until the engine suddenly lost power, it then ran roughly momentarily, before stopping. The pilot attempted to land the aircraft in the only available area, a confined swampy area, but during the approach it struck a large tree and crashed into the swamp. The inspection and testing of various components of helicopter was hampered by the aircraft having been submerged in the swamp, and no reason for the apparent loss of power could be determined.

The pilot arranged for a check flight in the aircraft, as it was a type he had not flown for some time. The instructor commented that as the pilot made rudder corrections during the takeoff roll, he also inadvertently applied light braking. After a period of general flying, the aircraft was returned to the circuit for a landing in moderate crosswind conditions. Touchdown was made in a three-point attitude, but shortly afterwards the aircraft commenced to swing to the right. Corrective measures by both pilots were unable to arrest the swing and the left gear subsequently collapsed. The pilot had used left aileron and right rudder inputs to align the aircraft at touchdown, and had possibly inadvertently applied braking to the right mainwheel.

The pilot was approaching to land in 10 knot crosswind conditions. Turbulence was encountered in the circuit area, and the pilot elected to approach at 80 knots with 20 degrees of flap selected. After a normal flare, the aircraft floated for half the 610 metre strip before touching down. The pilot applied heavy braking, but was unable to stop the aircraft within the confines of the strip. Damage was sustained as the aircraft passed through three drains. The approach speed was higher than required for the existing conditions. The strip sloped down in the direction of landing and it is probable that a tailwind existed at the time of landing.